Asked the same question on the Hunter site. Here are the replies. Question Answered. Something doesn't add up... Sounds like they were quoting you an entire new rodkicker (with gas spring). If you check out the Selden link in my previous post you will see that Selden provides the spring as a supplemental kit. You follow their charts, maybe make a boom diameter and length measurement to calculate weight, and choose the spring that is right for you. At the final installation you have the option to adjust the length by shortening a 'blank' aluminum tube used a space filler, increasing the length room for the spring itself. gas spring I've been meaning to put the gas spring in my 410 for years- finally asked Selden and was quoted $500! Not sure its worth that much- will check out other suppliers. Reply #4 Gas spring I just installed the boom-kicker gas spring insert on my H33. It took all of ten minute with no tools (!) required. The cost was $94.50 from my local rigging supplier. This will allow me to open my leech to change mainsail shape. Useful on light air days. Also, last year after a long blow (fall storm) the shackle connecting the topping lift to my boom came loose and I found my boom laying on the arch. No damage but the thought is the gas spring insert would have helped hold the boom up. Also I changed that shackle with one that you can put a split-ring through... The rigging supplier - Link submitted by author The relevant Selden page - Link submitted by author and search for Rodkicker Reply #3 Topping Lift I have been through this situation. Our boat came equipped with the Selden vang. It is included on our boats without a gas insert that supports the boom. I found it necessary to find another way to hold the boom off the arch when I changed the main to a large roach vertical batten sail. The topping lift would interfer with the roach. After several calls to my broker, Hunter and Selden I found that there is a gas insert that is only configured as an option in the Selden "Rodkicker" vang. I ordered it from the factory at a cost of somewhere around $125. Once installed, it worked like a champ. Reply #2 Rigid Vang on H-36 My H-36 was supplied with a rigid vang, but without the internal components to support the boom. I understand that these components can be ordered from Selden and retrofitted. I don't know it these components are springs, pnuematic, or hydraulic. Without the lifting component the topping lift is still necessary. The vang as supplied does increase the mechanical advantage compared to standard vangs. Reply #1 Vang is spring loaded With out a topping lift when I tghten the sheet down when leaving (no sail up)it would pull the boom down to the traveller arch. The boom on the traveller track would not be good. Topping lift is also heavy enough for a lift you to the top of the mast. Topping lift once set properly never needs ajustment.